Offseason
- October 2, 1978: Paul Siebert was traded by the Mets to the St. Louis Cardinals for Bob Coluccio.
- December 4, 1978: Bobby Brown was drafted by the Mets from the New York Yankees in the 1978 rule 5 draft.
- December 5, 1978: Tom Grieve and Kim Seaman were traded by the Mets to the St. Louis Cardinals for Pete Falcone.
- December 8, 1978: Jerry Koosman was traded by the Mets to the Minnesota Twins for a player to be named later and Greg Field (minors). The Minnesota Twins completed the trade by sending Jesse Orosco to the Mets on February 7, 1979.
- March 25, 1979: Bobby Brown was selected off waivers from the Mets by the Toronto Blue Jays.
- March 27, 1979: Nino Espinosa was traded by the Mets to the Philadelphia Phillies for Richie Hebner and José Moreno.
Read more about this topic: 1979 New York Mets Season